Merge tag 'for-linus-20180608' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few fixes for this merge window, where some of them should go in
  sooner rather than later, hence a new pull this week. This pull
  request contains:

   - Set of NVMe fixes, mostly follow up cleanups/fixes to the queue
     changes, but also teardown/removal and misc changes (Christop/Dan/
     Johannes/Sagi/Steve).

   - Two lightnvm fixes for issues that showed up in this window
     (Colin/Wei).

   - Failfast/driver flags inheritance for flush requests (Hannes).

   - The md device put sanitization and fix (Kent).

   - dm bio_set inheritance fix (me).

   - nbd discard granularity fix (Josef).

   - nbd consistency in command printing (Kevin).

   - Loop recursion validation fix (Ted).

   - Partition overlap check (Wang)"

[ .. and now my build is warning-free again thanks to the md fix  - Linus ]

* tag 'for-linus-20180608' of git://git.kernel.dk/linux-block: (22 commits)
  nvme: cleanup double shift issue
  nvme-pci: make CMB SQ mod-param read-only
  nvme-pci: unquiesce dead controller queues
  nvme-pci: remove HMB teardown on reset
  nvme-pci: queue creation fixes
  nvme-pci: remove unnecessary completion doorbell check
  nvme-pci: remove unnecessary nested locking
  nvmet: filter newlines from user input
  nvme-rdma: correctly check for target keyed sgl support
  nvme: don't hold nvmf_transports_rwsem for more than transport lookups
  nvmet: return all zeroed buffer when we can't find an active namespace
  md: Unify mddev destruction paths
  dm: use bioset_init_from_src() to copy bio_set
  block: add bioset_init_from_src() helper
  block: always set partition number to '0' in blk_partition_remap()
  block: pass failfast and driver-specific flags to flush requests
  nbd: set discard_alignment to the granularity
  nbd: Consistently use request pointer in debug messages.
  block: add verifier for cmdline partition
  lightnvm: pblk: fix resource leak of invalid_bitmap
  ...

1 files changed, 38 insertions, 30 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3ce607006c44..21e6d1b3b393 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -647,6 +647,36 @@ static void loop_reread_partitions(struct loop_device *lo,
 			__func__, lo->lo_number, lo->lo_file_name, rc);
 }
 
+static inline int is_loop_device(struct file *file)
+{
+	struct inode *i = file->f_mapping->host;
+
+	return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR;
+}
+
+static int loop_validate_file(struct file *file, struct block_device *bdev)
+{
+	struct inode	*inode = file->f_mapping->host;
+	struct file	*f = file;
+
+	/* Avoid recursion */
+	while (is_loop_device(f)) {
+		struct loop_device *l;
+
+		if (f->f_mapping->host->i_bdev == bdev)
+			return -EBADF;
+
+		l = f->f_mapping->host->i_bdev->bd_disk->private_data;
+		if (l->lo_state == Lo_unbound) {
+			return -EINVAL;
+		}
+		f = l->lo_backing_file;
+	}
+	if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
+		return -EINVAL;
+	return 0;
+}
+
 /*
  * loop_change_fd switched the backing store of a loopback device to
  * a new file. This is useful for operating system installers to free up
@@ -676,14 +706,15 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
 	if (!file)
 		goto out;
 
+	error = loop_validate_file(file, bdev);
+	if (error)
+		goto out_putf;
+
 	inode = file->f_mapping->host;
 	old_file = lo->lo_backing_file;
 
 	error = -EINVAL;
 
-	if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
-		goto out_putf;
-
 	/* size of the new backing store needs to be the same */
 	if (get_loop_size(lo, file) != get_loop_size(lo, old_file))
 		goto out_putf;
@@ -709,13 +740,6 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
 	return error;
 }
 
-static inline int is_loop_device(struct file *file)
-{
-	struct inode *i = file->f_mapping->host;
-
-	return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR;
-}
-
 /* loop sysfs attributes */
 
 static ssize_t loop_attr_show(struct device *dev, char *page,
@@ -881,7 +905,7 @@ static int loop_prepare_queue(struct loop_device *lo)
 static int loop_set_fd(struct loop_device *lo, fmode_t mode,
 		       struct block_device *bdev, unsigned int arg)
 {
-	struct file	*file, *f;
+	struct file	*file;
 	struct inode	*inode;
 	struct address_space *mapping;
 	int		lo_flags = 0;
@@ -900,29 +924,13 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
 	if (lo->lo_state != Lo_unbound)
 		goto out_putf;
 
-	/* Avoid recursion */
-	f = file;
-	while (is_loop_device(f)) {
-		struct loop_device *l;
-
-		if (f->f_mapping->host->i_bdev == bdev)
-			goto out_putf;
-
-		l = f->f_mapping->host->i_bdev->bd_disk->private_data;
-		if (l->lo_state == Lo_unbound) {
-			error = -EINVAL;
-			goto out_putf;
-		}
-		f = l->lo_backing_file;
-	}
+	error = loop_validate_file(file, bdev);
+	if (error)
+		goto out_putf;
 
 	mapping = file->f_mapping;
 	inode = mapping->host;
 
-	error = -EINVAL;
-	if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
-		goto out_putf;
-
 	if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) ||
 	    !file->f_op->write_iter)
 		lo_flags |= LO_FLAGS_READ_ONLY;